The main reason I heavily dislike the English Sonic X isn't even the censorship of language or symbolism and what not. While Sonic swearing like a sailor, and Rouge making BDSM jokes in the Japanese version and stuff is funny, I can obviously understand removing it.
My big problem is how they heavily change the dialogue to the point where the English version is a totally different show. The Japanese version felt like a nice way of seeing Sonic characters in different situations and giving insight to their character, while offering new characters.
The English version just feels like a bad superhero show where nothing has any emotional impact.
Sonic's confession to Amy, Molly's sacrifice, and Cosmos' sacrifice, are the biggest examples. They are some of the biggest, most emotional moments in the show that really delve into various characters, but they just butchered them. Hell, Sonic's confession to Amy was ENTIRELY removed! Like, there was NOTHING inappropriate about that scene, it was actually quite beautiful.
Also the soundtrack got completely butchered, as did the opening and ending sequences.
Necessary? No.
But her NOT dying doesn't take anything away from the show, either.
What? Shadow gets one less 14 year old girl who he feels responsible for the death of?
The original version of the scene was supposed to give off the feeling that Molly was honourably dying for her people, and later on, in the last episode, it's shown that Shadow comes to visit her grave, and that he values her as a friend. He doesn't even mope about it, he recognises her as a noble soldier.
The English version just has her chicken out at the last second and nothing is really built between her and Shadow as friends.